This set replaces the factory Recoil Spring Rod and Recoil Spring. It fits all full sized series 90 pistols except the 92A1, 96A1 and 90-TWO. It does not fit Compact, Centurion or Compact Type M pistols. The spring is slightly longer than the original factory spring, but is the same weight. Please note that due to supplier changes, the rod and spring may be chrome, stainless or black in color. Color changes do not affect performance.